1. Field of the Invention
The present invention relates to an apparatus for analyzing a program, checking the operation, and diagnosing faults in the microprocessor used in an apparatus such as a logic analyzer or microprocessor analyzer, etc.
2. Description of the Prior Art
In an apparatus for analyzing the operation of a microprocessor, when searching for specified trace data in the content of a trace memory, the display portion of the apparatus is used as follows: the picture is shifted by one line by operating scrolling up or scrolling down switches, i.e., after the address of the trace memory is input, the trace data displayed is examined to determine whether or not the specified trace data is displayed. When the specified trace data cannot be found in the displayed picture, the picture is shifted by one line by scrolling up or by scrolling down. The above operation is repeated until the specified trace data can be found. However, this operation requires much time and can be troublesome.
In particular, when analyzing a program, checking the operation, or diagnosing a fault in a microprocessor by using such an apparatus, it is frequently necessary to check at which point an internal register of a microprocessor is changed. Usually, many instructions exist in which the internal register of the microprocessor is changed, and frequently, the bus state of the microprocessor becomes a combination of several states when one such instruction is executed. Therefore, in the trace memory for storing the bus state, a combination of a plurality of trace data corresponding to each instruction is stored in the order by which the instructions are executed. To search for the trace data of the bus state when an instruction is given by which one of the internal registers of the microprocessor may be changed, it is necessary to not only search for the one specified data, but also to parallely shift the picture displayed or to repeat the operation for switching to the next picture display by determining in which of the combinations of the plurality of the trace data corresponding to the plurality of instruction by which the one of the internal registers may be changed, the trace data is coincident. This operation requires much time and can be very troublesome.